diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index 2234a3444f6e5..1a773557fc690 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -10405,19 +10405,20 @@ package android.service.translation {
     method @Nullable public final android.os.IBinder onBind(@NonNull android.content.Intent);
     method public void onConnected();
     method public void onCreateTranslationSession(@NonNull android.view.translation.TranslationContext, int, @NonNull java.util.function.Consumer<java.lang.Boolean>);
-    method @Deprecated public abstract void onCreateTranslationSession(@NonNull android.view.translation.TranslationContext, int);
+    method @Deprecated public void onCreateTranslationSession(@NonNull android.view.translation.TranslationContext, int);
     method public void onDisconnected();
     method public abstract void onFinishTranslationSession(int);
     method public abstract void onTranslationCapabilitiesRequest(int, int, @NonNull java.util.function.Consumer<java.util.Set<android.view.translation.TranslationCapability>>);
-    method public abstract void onTranslationRequest(@NonNull android.view.translation.TranslationRequest, int, @Nullable android.os.CancellationSignal, @NonNull android.service.translation.TranslationService.OnTranslationResultCallback);
+    method @Deprecated public void onTranslationRequest(@NonNull android.view.translation.TranslationRequest, int, @Nullable android.os.CancellationSignal, @NonNull android.service.translation.TranslationService.OnTranslationResultCallback);
+    method public void onTranslationRequest(@NonNull android.view.translation.TranslationRequest, int, @Nullable android.os.CancellationSignal, @NonNull java.util.function.Consumer<android.view.translation.TranslationResponse>);
     method public final void updateTranslationCapability(@NonNull android.view.translation.TranslationCapability);
     field public static final String SERVICE_INTERFACE = "android.service.translation.TranslationService";
     field public static final String SERVICE_META_DATA = "android.translation_service";
   }
 
-  public static interface TranslationService.OnTranslationResultCallback {
+  @Deprecated public static interface TranslationService.OnTranslationResultCallback {
     method @Deprecated public void onError();
-    method public void onTranslationSuccess(@NonNull android.view.translation.TranslationResponse);
+    method @Deprecated public void onTranslationSuccess(@NonNull android.view.translation.TranslationResponse);
   }
 
 }
diff --git a/core/java/android/service/translation/OnTranslationResultCallbackWrapper.java b/core/java/android/service/translation/OnTranslationResultCallbackWrapper.java
index f5851551d5c44..4f881b836cb36 100644
--- a/core/java/android/service/translation/OnTranslationResultCallbackWrapper.java
+++ b/core/java/android/service/translation/OnTranslationResultCallbackWrapper.java
@@ -17,7 +17,6 @@
 package android.service.translation;
 
 import android.annotation.NonNull;
-import android.annotation.Nullable;
 import android.os.DeadObjectException;
 import android.os.RemoteException;
 import android.util.Log;
@@ -25,6 +24,7 @@ import android.view.translation.TranslationResponse;
 
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
 
 /**
  * Callback to receive the {@link TranslationResponse} on successful translation.
@@ -32,13 +32,13 @@ import java.util.concurrent.atomic.AtomicBoolean;
  * @hide
  */
 final class OnTranslationResultCallbackWrapper implements
-        TranslationService.OnTranslationResultCallback {
+        Consumer<TranslationResponse> {
 
     private static final String TAG = "OnTranslationResultCallback";
 
     private final @NonNull ITranslationCallback mCallback;
 
-    private AtomicBoolean mCalled;
+    private final AtomicBoolean mCalled;
 
     /**
      * @hide
@@ -49,7 +49,7 @@ final class OnTranslationResultCallbackWrapper implements
     }
 
     @Override
-    public void onTranslationSuccess(@Nullable TranslationResponse response) {
+    public void accept(TranslationResponse response) {
         assertNotCalled();
         if (mCalled.getAndSet(response.isFinalResponse())) {
             throw new IllegalStateException("Already called with complete response");
@@ -66,15 +66,6 @@ final class OnTranslationResultCallbackWrapper implements
         }
     }
 
-    /**
-     * @deprecated use {@link #onTranslationSuccess} with error response instead.
-     */
-    @Override
-    @Deprecated
-    public void onError() {
-        // no-op.
-    }
-
     private void assertNotCalled() {
         if (mCalled.get()) {
             throw new IllegalStateException("Already called");
diff --git a/core/java/android/service/translation/TranslationService.java b/core/java/android/service/translation/TranslationService.java
index e7234ccc5dd2b..24ebe454f728c 100644
--- a/core/java/android/service/translation/TranslationService.java
+++ b/core/java/android/service/translation/TranslationService.java
@@ -125,7 +125,9 @@ public abstract class TranslationService extends Service {
 
     /**
      * Interface definition for a callback to be invoked when the translation is compleled.
+     * @deprecated use a {@link Consumer} instead.
      */
+    @Deprecated
     public interface OnTranslationResultCallback {
         /**
          * Notifies the Android System that a translation request
@@ -162,12 +164,12 @@ public abstract class TranslationService extends Service {
                 public void onTranslationRequest(TranslationRequest request, int sessionId,
                         ICancellationSignal transport, ITranslationCallback callback)
                         throws RemoteException {
-                    final OnTranslationResultCallback translationResultCallback =
+                    final Consumer<TranslationResponse> consumer =
                             new OnTranslationResultCallbackWrapper(callback);
                     mHandler.sendMessage(obtainMessage(TranslationService::onTranslationRequest,
                             TranslationService.this, request, sessionId,
                             CancellationSignal.fromTransport(transport),
-                            translationResultCallback));
+                            consumer));
                 }
 
                 @Override
@@ -242,8 +244,10 @@ public abstract class TranslationService extends Service {
      * instead.
      */
     @Deprecated
-    public abstract void onCreateTranslationSession(@NonNull TranslationContext translationContext,
-            int sessionId);
+    public void onCreateTranslationSession(@NonNull TranslationContext translationContext,
+            int sessionId) {
+        // no-op
+    }
 
     /**
      * TODO: fill in javadoc.
@@ -259,10 +263,45 @@ public abstract class TranslationService extends Service {
      * @param sessionId
      * @param callback
      * @param cancellationSignal
+     * @deprecated use
+     * {@link #onTranslationRequest(TranslationRequest, int, CancellationSignal, Consumer)} instead.
      */
-    public abstract void onTranslationRequest(@NonNull TranslationRequest request, int sessionId,
+    @Deprecated
+    public void onTranslationRequest(@NonNull TranslationRequest request, int sessionId,
             @Nullable CancellationSignal cancellationSignal,
-            @NonNull OnTranslationResultCallback callback);
+            @NonNull OnTranslationResultCallback callback) {
+        // no-op
+    }
+
+    /**
+     * Called to the service with a {@link TranslationRequest} to be translated.
+     *
+     * <p>The service must call {@code callback.accept()} with the {@link TranslationResponse}. If
+     * {@link TranslationRequest#FLAG_PARTIAL_RESPONSES} was set, the service may call
+     * {@code callback.accept()} multiple times with partial responses.</p>
+     *
+     * @param request
+     * @param sessionId
+     * @param callback
+     * @param cancellationSignal
+     */
+    //TODO: make abstract once aiai transitions.
+    public void onTranslationRequest(@NonNull TranslationRequest request, int sessionId,
+            @Nullable CancellationSignal cancellationSignal,
+            @NonNull Consumer<TranslationResponse> callback) {
+        onTranslationRequest(request, sessionId, cancellationSignal,
+                new OnTranslationResultCallback() {
+                    @Override
+                    public void onTranslationSuccess(@NonNull TranslationResponse response) {
+                        callback.accept(response);
+                    }
+
+                    @Override
+                    public void onError() {
+                        // null-op
+                    }
+                });
+    }
 
     /**
      * TODO: fill in javadoc